Accelerating pump channel vapor purging system



R. R. GRIFFEN Jan. 16, 1962 ACCELERATING PUMP CHANNEL VAPOR PURGINGSYSTEM 2 Sheets-Sheet 1 Filed Sept. 21, 1959 INVENTOR. RALPH R. GR FFENv! w M. w wi Jah. 16, 1962 R. R. GRIFFEN 3,017,167

ACCELERATING PUMP CHANNEL VAPOR PURGING SYSTEM Filed Sept. 21, 1959 2Sheets-Sheet 2 INVENTOR.

w RALPH R. GRIFFEN 22 2 ,@/%w&

ATTORNEYS i d States Patent 3,017,167 ACCELERATING PUMP CHANNEL VAPQRPURGING SYSTEM Ralph R. Griffen, Roseville, Mich, assignor to HolleyCarburetor Company, Van Dyke, Mich, a corporation of Michigan I FiledSept. 21, 195?, Ser. No. 841,232 15 Claims. (Cl. 261-340 This inventionrelates generally to pumps and more I of the carburetor body and pumpnozzle.

particularly to accelerating pumps used in carburetors 4 acceleraterapidly, the air flow through the carburetor V responds almostimmediately to the increased throttle opening; however, the fuel whichis heavier than air, lags a substantial amount behind the increased airfiow, thereby causing a leaning out of the fuel-air ratio. Theacceleratin-g'pump-is mechanically operated through the throttle linkageand is-designed to correctthis condition by supplying liquid fuel untilthe other fuel metering systems once again are providing the propermixture:

The performance of accelerating pumps, in general,

has been seriously impaired by fuel vapors trapped within theaccelerating pump system. The presence of these vapors is attributed tothose-situations where an excessive amount of heat is created'within theengine compartment, whether by a hot shutdown or prolonged idling of theengine. When vapor is trapped in the system, it displaces the volumetherein which liquid fuel would normally occupy and therefore, when theaccelerating pump is called upon to supply additional fuel underpressure into the mixing chamber of the carburetor, none will besupplied because of the absence of liquid'fuel.

An object of this invention is to provide means for removing the fuelvapor located within the accelerating pump system. I I

A further objectv of this invention is to provide a porous elementinaseries in the accelerating pump circuit at a point of high manifoldvacuum to provide a large diiferentiaLpressure between the inside andoutside of the porous element to cause the vapor to pass through thepores of the element and retain'the liquid-fuel in the pores. I

Another object of this invention is to overcome vapor lock which occursin an internal combustion engine by utilizing porous means in series inthe accelerating pump system which provides apressure differential whichpurges the channels of vapor and permits the channels to fill withliquid fuel. I

Still another object of the invention is toprovide a I simple,economical'and eflicient way to eliminate vapor lock in an internalcombustion engine by incorporating aporous filter in series in theaccelerating pump circuit at a point of high manifold vacuum to permitthe vapor to pass through the pores which retain the liquid fuel...2

Other objects and features-of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings, illustrating preferred. embodiments. of the.invention, wherein: L

FIGURE 1 isa side elevational view,'with portions thereof cut away andin cross-section, of a carburetor embodying the invention.

-. FIGURE 2 is a perspective view I of the carburetor,

"ice

2 again with portions thereof cu-t awayand in cross-section, and havingthe fuel-bowl removed with the exception of the accelerating pump andassociatedlinkage.

FIGURE 3 is an enlarged view'of the accelerating pu-mp no-zzle and theporous filter element in cross-sec tion, taken on a plane substantiallythrough the center Referring now in'greater detail to the drawings, FIG-URE 1 illustrates a carburetor 10 having a body 12"with an inductionpassage 14 extending therethrough. 'T-he carburetor 10 is provided withthe usual choke valve "16 controllingthe entrance of the air intake 18and throttle valve 20 controlling the flow of combustiblemixtureto theengine intake manifold 22.

A main fuel system is defined by metering restriction 24, conduits' 26and 28, and nozzle 30, which discharge as required within the inductionpassage 14. An idle system having a minimum idle and a transfer portionis schematically comprised of restriction '32, conduits 3 4 and 36, andport 38 and slot 49 which discharge selectively below the throttle-valve 20. A fuel bowl 42, defining a'chamber 44 and having an inlet46,'is secured as by screws 48 to the body 12 insuch a'manner to supplyall the fuel systems with a source of fuel." An accelerating pump 50 isattached to the bottom of the fuel bowl 42 and is adapted to be actuatedin a well known manner by levers 52 and 53' (shown in FIGURE 2)' whenthe throttle 20 isopened. The accelerating pump 50 supplies theadditional fuel for fastacceleration when the throttle valve 20issuddenly opened.- FIGURE 2 illustrates the accelerating pump 50 asbeing comprised of a reinforced diaphragm 54 secured to the bottom ofthe fuel bowl 42 by a member--56 and thereby crea-t-ing-achamber 58. The-diaphragrn54-is acted on by a returnspringES. The chamber 58communicates with chamber 44 of the fuel bow-l '42 by means of passage59having a gravity actuated ball check valve 60. Chamber 58 alsocommunicates with the pump nozzle assembly 62 by means of conduits 64,66 and 70.

A passage 88 having a restriction 90 therein leads from theengineintake' manifold 22 to passage '66. 'The passage 88 has anannular-chamber 67 in which is 10- cateda porous filter element 71, asis :best shown in FIGUREG'. Another chamber, identified as numeral 69,provides an annular space around the porous filter element 71- in whichthe vacuum frornthe engine intake manifold 22-or from another-source=of-vacuum acts to provide large differential pressure between theinside-and outside of the" filter element 71 to permit vapor to passfrom the channels or passages through the pores and to prevent passageof the liquid'fuel, as will be explained in more detail later. Y 2

The porous element 71 may be made of any porous material which willprovide a proper dilferentialpressure. As an example, a powdered'metalora plastic mate'rial may be-used. If a cylindrical powdered metalbushing or filter is used, the -filter may beconstructed of a relativelysmall size. As'an example, the powdered metal filter could have'aninside diameter. of a .127" an outside diameter 0f-.253,'and anoveralllength of'.375-. -'-Element 71, as illustrated, is annular-andsubstantially fills the annular chamber67, as previouslv explained.

- A screw 72 and housing 74 cooperativelydefining' a chamber 76constitute the basicnozzle'as sembly.--.-A nozzle-78; which may eitherbeformed as part of housing 7 4- 'or' secured thereto, communicates withchamber 76 and is directed towards the induction passage 14. The. screw72 is threadedly received by the body,12, andv'a passagev 80 formed inscrew 72 is provided as a means of communication between chamber 76 andconduit 70. A seat 82 is providedwithinconduit 70 anda ball '84 andweight 85 are placed between the'seatand chamber 76.

In operation when the throttle 20 is opened, the pump linkages 52. and53 force the pump diaphragm 54 upwardly. As the diaphragm 54 moves up,the pressure forces the pump inlet ball check valve 60 closed, therebypreventing fuel from flowing back into the chamber 44. The fuel withinchamber 58 flows from there through passages or channels 64, 66 and 70where it causes the ball 84- and weight 86 to raise, thereby dischargingthe fuel from chamber 76 through nozzle 78 into the induction passage14.

As the throttle 20 is moved toward the closed position, the linkages 52and 53 return to their normal positions, and the diaphragm 54 is forceddownwardly by spring 55. As the diaphragm 54 returns to its originalposition the pump inlet ball check valve 60 is opened and chamber 58 isagain filled with fuel from the fuel bowl 42.

The invention relates to improvements in pump channel vapor or gaspurging systems. The invention is particularly valuable when hotinternal combustion engines vaporize fuel in the channels or passageswhich due to increased volume and pressure causes poor acceleration.This condition is worse on hot days after a car has been shut off andnot used for fifteen minutes to thirty minutes. On starting up and uponlight tip ins of the accelerator pedal the automobile without such avapor purging system shows a jerky hesitation because the channels andpassages are vapor locked due to the ball weight 84 at the top of thechannel 70.

The specific improvement contemplated by the invention is theincorporation of the porous filter 71 in the annular chamber 67 ofchannel or passage 88 and connecting the inside periphery of the hollowcylindrical filter 71 to the passage 66 at a point of high manifoldvacuum to provide a large dilferential pressure between the inside andoutside of the filter 71 to cause the vapor in the channels or passages64, 66 and 70 to pass through the pores of the filter 71 into thepassage 88. By utilizing such an arrangement it is possible to obtain apressure differential of approximately pounds per square inch to purgethe passages of vapor and thereby permit the channels to fill withliquid fuel.

When the engine is started on which the carburetor 10 is mounted andbecome self-sustaining, manifold vacuum will be applied to passage 88 tocreate a pressure differential between it and the passages 64, 66 and70. This will cause the vapors which are present in the system to beforced out through the pores in the filter element 71 into the passage88 and subsequently to the engine. Since a vacuum is constantly appliedto the system during engine operation, no vapors will collect evenduring excessively long periods of idle operations.

While the form of the embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

The drawings and the foregoing specification constitute a description ofthe improved accelerating pump channel vapor purging system in suchfull, clear, concise and exact terms as to enable any person skilled inthe art to practice the invention, the scope of which is indicated bythe appended claims.

What I claim as my invention is:

1. An accelerating pump system comprising: a carburetor having a mixingchamber; an accelerating pump having a fuel chamber therein forsupplying additional fuel to the mixing chamber; a first passageconnecting saidfuel chamber to said mixing chamber; a second passageleading from a source of vacuum to said first passage; and a porousfilter element at the intersection between said first and secondpassages to provide free fuel flow along said first passage and tointercept fuel flow from said first to said second passages, said filterelement having pores of such size as to provide purging of the vapor insaid first passage through the pores in said element and to prevent thepassage of liquid fuel through the pores of the element.

2. An accelerating pump system comprising: a carburetor having a mixingchamber; an accelerating pump having a fuel chamber therein forsupplying additional fuel to the mixing chamber; a first passageconnecting said fuel chamber to said mixing chamber; valve means in saidfirst passage for controlling fuel flow from said fuel chamber to saidmixing chamber; a second passage leading from a source of vacuum to saidfirst passage; and a porous filter element at the intersection betweensaid first and second passages to provide free fuel flow along saidfirst passage and to intercept fuel flow from said first to said secondpassages, said filter element having pores of such size as to providepurging of the vapor in said first passage through the pores in saidelement and to prevent the passage of liquid fuel through the pores ofthe element.

3. An accelerating pump system comprising: a carburetor; a mixingchamber in said carburetor and having a discharge nozzle therein; anaccelerating pump having a fuel chamber therein for supplying additionalfuel to the mixing chamber; a discharge passage connecting said fuelchamber to said mixing chamber through said nozzle; valve means forcontrolling fuel flow from said fuel chamber to said mixing chamber; avacuum passage extending from an engine operated vacuum source to saiddischarge passage; and a porous filter element at the intersectionbetween said discharge and vacuum passages in position to provide freefuel fiow along said discharge passage and to intercept flow from saiddischarge passage to said vacuum passage, said filter element havingpores of such a size to provide purging of the vapor in said dischargepassage through the pores in said element and to prevent passing of fuelthrough the pores.

4. An accelerating pump system comprising: a carburetor; a mixingchamber in said carburetor; a discharge nozzle extending into saidmixing chamber for delivering a small quantity of fuel required for fastacceleration; an accelerating pump provided with a fuel chamber; a firstpassage connecting said fuel chamber to said mixing chamber through saidnozzle; a second passage leading from a source of engine operated vacuumto said discharge passage; and a porous filter element at theintersection between said first and second passages to provide free fuelflow along said first passage and to intercept fuel flow from said firstto said second passages, said element having pores of such a sizewhereby a differential pressure between the inside and outside of saidfilter element is effective to purge the vapor in said first passagethrough the pores, said element preventing the fuel from passing intosaid second passage.

5. An accelerating pump system comprising: a carburetor; a mixingchamber in said carburetor; a discharge nozzle extending into saidmixing chamber for delivering a small quantity of fuel required for fastacceleration; an accelerating pump provided with a fuel chamber; aliquid fuel passage connecting said fuel chamber to said mixing chamberthrough said nozzle; valve means in said fuel passage for controllingfuel flow from said fuel chamber to said mixing chamber; a vacuumpassage extending from a source of engine generated Vacuum to saidliquid fuel passage; and a porous filter element located in said vacuumpassage at the place where said passages intersect, said element havingpores of such a size whereby a differential pressure between the insideand outside of said filter element is established to purge the vaporinsaid fuel passage through the pores in said filter element, saidelement preventing the fuel from passing through the pores.

6. An accelerating pump system comprising: a carburetor; a mixingchamber in said carburetor; a discharge nozzle extending into saidmixing chamber for delivering a small quantity of fuel required for fastacceleration; an accelerating pump provided with a fuel chamber; a fuelpassage connecting said fuel chamber to said mixing chamber through saidnozzle; check valve means for controlling fluid flow in said passage tosaid mixing chamber;

a vacuum passage extending from a source of-engine operated vacuum tosaid fuel passage; and a porous filter element at the intersectionbetween said fuel and vacuum passages in position to provide free fuelflow along said fuel passage and to intercept fuel from said fuelpassage to said vacuum passage, said element having pores of such a sizewhereby a relatively high differential pressure created between theinside and outside of said filter element permits the vapor in said fuelpassage to be purged from said fuel passage through the pores in saidelement, said element preventing fuel from passing through said pores.

7. An accelerating pump system comprising: a carburetor having a mixingchamber; a throttle valve movably mounted in said mixing chamber; a fuelchamber; a discharge passage connecting said fuel chamber to said mixingchamber; a diaphragm movable in said fuel chamber for deliveringadditional fuel to said mixing chamber when the throttle valve issuddenly opened; a vacuum passage extending from the engine manifold tosaid discharge passage; and a porous filter element at the intersectionbetween said discharge and vacuum passages in position to provide freefuel fiow along said discharge pas sage and to intercept flow from saiddischarge passage to said vacuum passage, said element having pores ofsuch size to provide purging of the vapor in said discharge passageoutwardly through the pores in said filter element into said vacuumpassage, said filter element preventing the liquid fuel from passingthrough the pores.

8. An accelerating pump system comprising: a carburetor having a mixingchamber; a throttle valve movably mounted in said carburetor; a fuelchamber; a fuel bowl; an inlet valve connecting said fuel bowl to saidfuel chamher; a first passage connecting said fuel chamber to saidmixing chamber; an outlet valve for controlling fuel flow in said firstpassage between said chambers; a diaphragm movable in said fuel chamberfor delivering additional fuel to said mixing chamber when said throttlevalve is suddenly opened; a second passage connected to the enginemanifold and to said first passage; and porous filter means at theintersection between said first and second passages, said filter meanshaving pores of such size to purge vaporous gases in said first passagethrough the pores in said filter means, said filter means preventing theliquid fuel from passing through the pores but permitting the fuel fromthe fuel chamber to travel in said first passage unimpeded between saidfuel chamber and said mixing chamber.

9. An accelerating pump system comprising: a carburetor having a mixingchamber; a throttle valve movably mounted in said carburetor; a fuelchamber; a fuel bowl; an inlet Valve connecting said fuel bowl to saidfuel chamber; a first passage connecting said fuel chamber to saidmixing chamber; an outlet valve for controlling fuel flow in said firstpassage between said chambers; a diaphragm movable in said fuel chamberfor delivering additional fuel to said mixing chamber when said throttlevalve is suddenly opened; a second passage connected to the enginemanifold and to said first passage; an annular chamber at the placewhere said second passage joins said first passage; a porous filterelement located in said annular chamber; means forming an annular spacearound said element to provide vacuum around the outer periphery of saidelement; said element having pores of such size to provide purging ofthe vapor in said first passage through the pores and to prevent fuelfrom passing through the pores.

10. An accelerating pump system comprising: a carburetor having a mixingchamber; a throttle valve movably mounted in said mixing chamber; a fuelchamber; a discharge passage connecting said fuel chamber to said mixingchamber; a diaphragm movable in said fuel chamber for deliveringadditional fuel to said mixing chamber ing an annular space around saidelement to provide vaci uum 0n the outer periphery of said element; saidelement having pores of such a size to purge thevapor in said dischargepassage through the pores and toprevent the fuel from passing throughthe pores.

11. An accelerating pump system comprising: a carburetor; a mixingchamber in said carburetor and having a discharge nozzle therein; anaccelerating pump having a fuel chamber therein for supplying additionalfuel to the mixing chamber; a discharge passage connecting said fuelchamber to said mixing chamber through said nozzle; valve means forcontrolling fluid fiow from said fuel chamber to said mixing chamber; avacuum passage extending from an engine operated vacuum source to saiddischarge passage; an annular chamber at the end of said vacuum passageextending to said discharge passage; a porous filter element located insaid chamber; means forming an annular space around said element toprovide vacuum on the outer periphery of said element; said elementhaving pores of such a size to purge the vapor in said discharge passagethrough the pores and to prevent the fuel from passing through thepores.

12. An accelerating pump system comprising: a carburetor having a mixingchamber; an accelerating pump having a fuel chamber therein forsupplying additional fuel to the mixing chamber; a first passageconnecting said fuel chamber to said mixing chamber; a second passageleading from a source of vacuum to said first passage; an annularchamber at the place where said second passage joins said first passage;an annular porous filter element located in said annular chamber; meansforming an annular space around said element to provide vacuum aroundthe outer periphery of said element; said element having pores of suchsize to provide purging of the vapor in said first passage through thepores and to prevent fuel from passing through the pores.

13. An accelerating pump system comprising: a carburetor having a mixingchamber; an accelerating pump having a fuel chamber therein forsupplying fuel to the mixing chamber; a first passage connecting saidfuel chamber to said mixing chamber; a second passage leading from asource of engine manifold vacuum to said first passage; and porousfilter means at the intersection between said first and second passagesto provide free fuel flow along said first passage and to intercept fuelflow from said first to said second passages, said filter means havingpores of such a size to purge the vapor in said first passage throughthe pores and to prevent fuel from passing through the pores.

14. An accelerating pump system comprising: a carburetor having a mixingchamber; an accelerating pump having a fuel chamber therein forsupplying fuel to the mixing chamber; a first passage connecting saidfuel chamber to said mixing chamber; a second passage leading from asource of engine vacuum to said first passage; means forming a chamberat the place where said second passage joins said first passage; porousfilter means located in said chamber in position to provide free fuelflow along said first passage and to intercept fuel flow from said firstto said second passages; and means forming a space around said filtermeans to provide vacuum around the outer periphery of said filter means;said filter means having pores of such a size to purge the vapor in saidfirst passage through the pores and to prevent the fuel from passingthrough the pores.-

15. An accelerating pump system comprising: a carburetor having a mixingchamber; an accelerating pump having a fuel chamber therein forsupplying additional fuel to the mixing chamber; a first passageconnecting said fuel chamber to said mixing chamber; said first passagehaving an annular chamber surrounding an intermediate portion thereof; atubular filter in said annular chamber having its outer surface spacedinwardly from the outer surface of said annular chamber to definetherewith an annular space and having an opening therethrough inalignment with said first passage to provide substantially unrestrictedfuel flow along said first passage; a second passage leading from asource of vacuum to the annular space surrounding said filter, saidfilter having pores of such size to provide purging of the vapor Q insaid first passage through the pores and to prevent fuel from passingthrough the pores.

References Cited in the file of this patent UNITED STATES PATENTS

